Post quantum signatures need blockchain specific features for secure use
Domain Specific Post Quantum Signatures for Blockchains
Cryptography and Security
Summary
Blockchain systems require special kinds of digital signatures to stay secure against future quantum computers. The authors show that just having single-user quantum-resistant signatures isn't enough. They analyze many existing signature methods and argue that blockchains need signatures tailored to their specific roles and needs, such as stable transaction tracking and verifying groups of signers. Their work points out that current post-quantum signature methods can't directly replace what blockchains use today without adapting to these unique demands.
What this means in practice
- •For blockchain developers: Design consensus-aware signature schemes that meet blockchain-specific security and operational needs against quantum attacks.
- •For cryptocurrency protocol designers: Adapt cryptographic signatures to support stable transaction IDs, committee rotation, and evidence accountability in blockchain networks.
Authors
Maja Lie, Ben Marsh
Abstract
Blockchains need more than post quantum single signer signatures. They need consensus profiled authentication objects with canonical bytes, priced invalid input rejection, stable transaction identifiers, hybrid downgrade resistance, public aggregation, merge semantics, accountable signer evidence, forward secure committee rotation, and light client consequences. We argue for domain specific post quantum signatures for blockchain roles, analogously to how hash function engineering produced domain specific primitives for hash table DoS and arithmetized proof systems. We formalize transaction authorization and quorum certificate requirements, instantiate them on Bitcoin, Ethereum, and a Sei Giga style high throughput BFT stress profile, and evaluate ML-DSA, SLH-DSA, Falcon/FN-DSA, HAWK, MAYO, SNOVA, UOV/QR-UOV, FAEST, SQIsign, LaBRADOR Falcon, Squirrel, Chipmunk, and DKKW/LeanSig. The conclusion is blunt. NIST single signer signatures are necessary components, although none of the current schemes is a drop in replacement for the signature layer of modern public blockchains. The missing object is a consensus ready post quantum signature profile, not another generic size table.